Method and apparatus for automotive variable impedance touch sensor array

ABSTRACT

The present invention relates to automotive interface systems and methods. In one embodiment, an automotive interface system includes a steering wheel and an integrated interpolated variable impedance array that comprises a grid of sensing elements. The sensing elements are configured to power on simultaneously and to simultaneously generate multiple currents along multiple current paths in response to sensing a touch wherein the amount of current generated by a sensing element of the grid is directly proportional to the force applied by the touch. The automotive interface system also includes an analog-to-digital converter (ADC) and a processor communicatively coupled to the interpolated variable impedance array that are configured to receive the multiple currents along multiple current paths and determine a location, a duration, an area, and a force of the touch from the multiple currents along multiple current paths.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/414,419, filed May 16, 2019, entitled “METHOD AND APPARATUS FORAUTOMOTIVE VARIABLE IMPEDANCE TOUCH SENSOR ARRAY,” which claims priorityto U.S. Provisional Patent Application No. 62/730,757, entitled “METHODAND APPARATUS FOR AUTOMOTIVE VARIABLE IMPEDANCE TOUCH SENSOR ARRAY,”filed on Sep. 13, 2018, the disclosures of which are hereby expresslyincorporated herein by reference in their entireties.

INTRODUCTION

The present invention relates to automotive touch sensor detectorsystems and methods incorporating an interpolated variable impedancetouch sensor array. The systems and methods disclosed herein utilize atouch sensor array configured to detect proximity/contact/pressure via avariable impedance array electrically coupling interlinked impedancecolumns coupled to an array column driver and interlinked impedance rowscoupled to an array row sensor. The array column driver is configured toselect the interlinked impedance columns based on a column switchingregister and electrically drive the interlinked impedance columns usinga column driving source. The variable impedance array conveys currentfrom the driven interlinked impedance columns to the interlinkedimpedance columns sensed by the array row sensor. The array row sensorselects the interlinked impedance rows within the touch sensor array andelectrically senses the interlinked impedance rows state based on a rowswitching register. Interpolation of array row sensor sensedcurrent/voltage allows accurate detection of touch sensor arrayproximity/contact/pressure and/or spatial location.

The gesture recognition systems and methods using variable impedancearray sensors include sensors disclosed in the following applications,the disclosures of which are hereby incorporated by reference in theirentirety: U.S. patent application Ser. No. 15/599,365 titled SYSTEM FORDETECTING AND CONFIRMING A TOUCH INPUT filed on May 18, 2017; U.S.patent application Ser. No. 15/653,856 titled TOUCH SENSOR DETECTORSYSTEM AND METHOD filed on Jul. 19, 2017 and issued as U.S. Pat. No.10,073,565 on Sep. 11, 2018; U.S. patent application Ser. No. 15/271,953titled DIAMOND PATTERNED TOUCH SENSOR SYSTEM AND METHOD filed on Sep.21, 2016; U.S. patent application Ser. No. 14/499,090 titled CAPACITIVETOUCH SENSOR SYSTEM AND METHOD filed on Sep. 27, 2014 and issued as U.S.Pat. No. 9,459,746 on Oct. 4, 2016; U.S. patent application Ser. No.14/499,001 titled RESISTIVE TOUCH SENSOR SYSTEM AND METHOD filed on Sep.26, 2014 and issued as U.S. Pat. No. 9,465,477 on Oct. 11, 2016; U.S.patent application Ser. No. 15/224,003 titled SYSTEMS AND METHODS FORMANIPULATING A VIRTUAL ENVIRONMENT filed on Jul. 29, 2016 and issued asU.S. Pat. No. 9,864,461 on Jan. 9, 2018; U.S. patent application Ser.No. 15/223,968 titled SYSTEMS AND METHODS FOR MANIPULATING A VIRTUALENVIRONMENT filed on Jul. 29, 2016 and issued as U.S. Pat. No. 9,864,460on Jan. 9, 2018; U.S. patent application Ser. No. 15/470,669 titledSYSTEM AND METHOD FOR DETECTING AND CHARACTERIZING FORCE INPUTS ON ASURFACE filed on Mar. 27, 2017; and U.S. patent application Ser. No.15/476,732 titled HUMAN-COMPUTER INTERFACE SYSTEM filed on Oct. 5, 2017.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned objects and advantages of the present invention, aswell as additional objects and advantages thereof, will be more fullyunderstood herein after as a result of a detailed description of apreferred embodiment when taken in conjunction with the followingdrawings in which:

FIG. 1 illustrates an exemplary variable impedance touch sensor arraywith interlinked impedance columns and interlinked impedance rows.

FIG. 2 illustrates an exemplary column switching register, row switchingregister, interlinked impedance column, and interlinked impedance row ofan exemplary variable impedance touch sensor array.

FIG. 3 illustrates an exemplary variable impedance touch sensor array.

FIG. 4 illustrates an automotive touch sensor detector system using anexemplary interpolated variable impedance sensor array.

FIG. 5 illustrates an automotive touch sensor detector system using anexemplary interpolated variable impedance sensor array.

FIG. 6 illustrates an exemplary grip or squeeze pattern using anautomotive touch sensor detector incorporating an interpolated variableimpedance touch sensor array.

FIG. 7 illustrates an automotive touch sensor detector system using anexemplary interpolated variable impedance sensor array.

FIG. 8 illustrates an automotive touch sensor detector system using anexemplary interpolated variable impedance sensor array.

FIG. 9 illustrates an automotive touch sensor detector system using anexemplary interpolated variable impedance sensor array.

FIG. 10 illustrates an automotive touch sensor detector system using anexemplary interpolated variable impedance sensor array.

FIG. 11 illustrates a method of using an automotive touch sensordetector system using an exemplary interpolated variable impedancesensor array.

FIG. 12 illustrates a method of using an automotive touch sensordetector system using an exemplary interpolated variable impedancesensor array.

DETAILED DESCRIPTION

The present invention relates to automotive touch sensor detectorsystems and methods incorporating an interpolated variable impedancetouch sensor array. The systems and methods disclosed herein utilize atouch sensor array configured to detect proximity/contact/pressure via avariable impedance array electrically coupling interlinked impedancecolumns coupled to an array column driver and interlinked impedance rowscoupled to an array row sensor. The array column driver is configured toselect the interlinked impedance columns based on a column switchingregister and electrically drive the interlinked impedance columns usinga column driving source. The variable impedance array conveys currentfrom the driven interlinked impedance columns to the interlinkedimpedance columns sensed by the array row sensor. The array row sensorselects the interlinked impedance rows within the touch sensor array andelectrically senses the interlinked impedance rows state based on a rowswitching register. Interpolation of array row sensor sensedcurrent/voltage allows accurate detection of touch sensor arrayproximity/contact/pressure and/or spatial location.

In one embodiment, the present invention relates to automotive interfacesystems and methods. In one embodiment, an automotive interface systemincludes a steering wheel and an integrated interpolated variableimpedance array that comprises a grid of sensing elements. The sensingelements are configured to power on simultaneously and to simultaneouslygenerate multiple currents along multiple current paths in response tosensing a touch wherein the amount of current generated by a sensingelement of the grid is directly proportional to the force applied by thetouch. The automotive interface system also includes ananalog-to-digital converter (ADC) and a processor communicativelycoupled to the interpolated variable impedance array that are configuredto receive the multiple currents along multiple current paths anddetermine a location, a duration, an area, and a force of the touch fromthe multiple currents along multiple current paths.

In some embodiments, the interpolated variable impedance array isdisposed on the front side of the steering wheel. And in otherembodiments, the interpolated variable impedance array is disposed onthe back side of the steering wheel.

The interpolated variable impedance array may also comprise swipeableand/or pressable controls.

In other embodiments, the interpolated variable impedance array and theprocessor are configured to control one or more of the automobile'sheadlights, wipers, or blinkers. Additionally, the interpolated variableimpedance array and the processor may be configured to determine anamount of pressure applied to the variable impedance touch sensor array.And the interpolated variable impedance array and the processor may beconfigured to control an audio source relative to the amount of pressureapplied to the variable impedance touch sensor array.

In additional embodiments, the interpolated variable impedance array andthe processor are configured to detect a driver's grip force of thesteering wheel. And the interpolated variable impedance array and theprocessor may be configured to apply a control signal based on thedriver's grip force of the steering wheel. Similarly, the interpolatedvariable impedance array and the processor may be configured to apply acontrol signal based on a pattern of the driver's grip force of thesteering wheel.

In certain embodiments, the interpolated variable impedance array andthe processor are configured to determine that the driver's grip forceof the steering wheel is inadvertent or spurious. And the interpolatedvariable impedance array and the processor may be configured todetermine when the driver is not gripping the steering wheel above athreshold level. In systems implemented in autonomous or semiautonomousvehicles, the processor may further be configured to send a signal tocause an autonomous or semiautonomous vehicle to return control to adriver. Moreover, the interpolated variable impedance array and theprocessor may be configured to determine when a driver has only one handon the steering wheel.

In one embodiment, an automotive interface system includes a seat beltand an integrated interpolated variable impedance array that comprises agrid of sensing elements. The sensing elements are configured to poweron simultaneously and to simultaneously generate multiple currents alongmultiple current paths in response to sensing a touch wherein the amountof current generated by a sensing element of the grid is directlyproportional to the force applied by the touch. The automotive interfacesystem also includes an ADC and a processor communicatively coupled tothe interpolated variable impedance array that are configured to receivethe multiple currents along multiple current paths and determine alocation, a duration, an area, and a force of the touch from themultiple currents along multiple current paths.

In a related embodiment, the interpolated variable impedance array isincorporated in a fabric portion of the seat belt. In anotherembodiment, the interpolated variable impedance array and the processorare configured to determine a fit of the seat belt on a passenger. Theinterpolated variable impedance array and the processor may also beconfigured to determine instantaneous force signatures and patterns overtime to determine that the fit of the seat belt. And the interpolatedvariable impedance array and the processor may be configured to send acontrol signal to realign a seat based on the instantaneous forcesignatures and patterns over time.

In another embodiment, an automotive interface system includes anaccelerator pedal and an integrated interpolated variable impedancearray that comprises a grid of sensing elements. The sensing elementsare configured to power on simultaneously and to simultaneously generatemultiple currents along multiple current paths in response to sensing atouch wherein the amount of current generated by a sensing element ofthe grid is directly proportional to the force applied by the touch. Theautomotive interface system also includes an ADC and a processorcommunicatively coupled to the interpolated variable impedance arraythat are configured to receive the multiple currents along multiplecurrent paths and determine a location, a duration, an area, and a forceof the touch from the multiple currents along multiple current paths.

FIGS. 1-3 illustrate an exemplary variable impedance touch sensor array100, 200, 300 including interlinked impedance columns and interlinkedimpedance rows as well as an exemplary column switching register, rowswitching register, interlinked impedance column, and interlinkedimpedance row. FIG. 1 illustrates an exemplary variable impedance array110, interlinked impedance columns 120, and interlinked impedance rows130. Here the variable impedance array 110 includes columns 112 and rows113 of an array in which individual variable impedance array elements119 may interconnect within the row/column cross points of the array.These individual variable impedance array elements 119 may compriseactive and/or passive components based on the application context, andinclude any combination of resistive, capacitive, and inductivecomponents. Thus, the variable impedance array 110 array impedanceelements (0319) are depicted generically in this diagram as generalizedimpedance values Z.

The physical variable impedance array columns 112 and variable impedancearray rows 113 are connected via interlinked impedance columns 120 andinterlinked impedance rows 130, respectively. The interlinked impedancecolumns 120 and interlinked impedance rows 130 are configured to reducethe number of columns and rows that are connected to the column drivesources 121, 123, 125 and the row sense sinks 131, 133, 135. As such,the combination of the interlinked impedance columns 120 and interlinkedimpedance rows 130 will reduce the external components necessary tointerface to the variable impedance array columns 112 and variableimpedance array rows 113. Within the context of the present invention,the number of interlinked impedance columns 120 interconnects will beconfigured to allow the reduction of the number of column drive sources121, 123, 125 to less than the number of physical variable impedancearray columns 112 (thus the number of external interlinked impedancecolumns is typically less than the number of internal interlinkedimpedance columns columns), and the interlinked impedance rows 130interconnects will be configured to allow the reduction of the number ofrow sense sinks 131, 133, 135 to less than the number of physicalvariable impedance array rows 113 (thus the number of externalinterlinked impedance rows is typically less than the number ofinterlinked impedance rows rows). This reduction is achieved by havingone or more interlinked impedance columns 120 elements 129 in seriesbetween each variable impedance array physical column 112 and one ormore interlinked impedance rows 130 elements 139 between each variableimpedance array physical row 113. Thus, the XXY variable impedance arraysensor 110 is translated to an electrical interface only requiring Pcolumn drivers and Q row sensors. The present invention constrains P≤Xand Q≤Y with many preferred embodiments satisfying the relations X/P≥2or Y/Q≥2.

Note that within the context of these preferred embodiments, there maybe circumstances where the interlinked impedance columns may incorporatea plurality of interlinked impedances with the interlinked impedancerows incorporating a singular interlinked impedance element, andcircumstances where the interlinked impedance columns may incorporate asingular interlinked impedance element with the interlinked impedancerows incorporating a plurality of interlinked impedance elements.

The interlinked impedance columns 120 impedance elements 129 areconfigured to connect individual variable impedance array columns 112.These interlinked impedance columns 120 impedance elements 129 maycomprise active and/or passive components based on the applicationcontext and include any combination of resistive, capacitive, andinductive components. Thus, the interlinked impedance columns 120impedance elements 129 are depicted generically in this diagram asgeneralized impedance values X. As depicted in the diagram, theindividual variable impedance array columns may either be directlydriven using individual column drive sources 121, 123, 125 orinterpolated 122, 124 between these directly driven columns.

The interlinked impedance rows 130 impedance elements 139 are configuredto connect individual variable impedance array rows 113. Theseinterlinked impedance rows 130 impedance elements 139 may compriseactive and/or passive components based on the application context andinclude any combination of resistive, capacitive, and inductivecomponents. Thus, the interlinked impedance rows 130 impedance elements139 are depicted generically in this diagram as generalized impedancevalues Y. As depicted in the diagram, the individual variable impedancearray rows may either be directly sensed using individual row sensesinks 131, 133, 135 or interpolated 132, 134 between these directlysensed rows.

The column drive sources 121, 123, 125 are generically illustrated asbeing independent in this diagram but may be combined in someconfigurations utilizing a series of switches controlled by a columnswitching register that defines the type of column drive source to beelectrically coupled to each column that is externally accessible to thevariable impedance array sensors 110. Variations of AC/DC excitation,voltage sources, open circuits, current sources, and other electricalsource driver combinations may be utilized as switched configurationsfor the column drive sources 121, 123, 125. The column switchingregister may be configured to both select the type of electrical sourceto be applied to the variable impedance array sensors 110 but also itsrelative amplitude/magnitude.

The row sense sinks 131, 133, 135 are generically illustrated as beingindependent in this diagram but may be combined in some configurationsutilizing a series of switches controlled by a row switching registerthat defines the type of row sense sinks to be electrically coupled toeach row that is externally accessible to the variable impedance arraysensors 110. Variations of AC/DC excitation, voltage sources, opencircuits, current sources, and other electrical sense sink combinationsmay be utilized as switched configurations for the row sense sinks 131,133, 135. The row switching register may be configured to both selectthe type of electrical sink to be applied to the variable impedancearray sensors 110, but also its relative amplitude/magnitude.

Further detail of the column switching register and row switchingregister column/row source/sink operation is depicted in FIG. 2 (200)wherein the variable impedance array 210 is interfaced via the use ofthe interlinked impedance columns 212 and interlinked impedance rows 213impedance networks to column drive sources 221, 223, 225 and row sensesinks 231, 233, 235, respectively. The column switching registers 220may comprise a set of latches or other memory elements to configureswitches controlling the type of source drive associated with eachcolumn drive source 221, 223, 225, the amplitude/magnitude of the drivesource, and whether the drive source is activated. Similarly, the rowswitching registers 230 may comprise a set of latches or other memoryelements to configure switches controlling the type of sense sinkassociated with each row sense sink 231, 233, 235, theamplitude/magnitude of the sink, and whether the sink is activated.

As mentioned previously, the interlinked impedance columns 212 andinterlinked impedance rows 213 impedance networks may comprise a widevariety of impedances that may be static or actively engaged by theconfiguration of the column switching register 220 and row switchingregister 230, respectively. Thus, the column switching register 220 androw switching register 230 may be configured in some preferredembodiments to not only stimulate/sense the variable impedance array 210behavior, but also internally configure the interlinked nature of thevariable impedance array 210 by reconfiguring the internal columncross-links and the internal row cross-links. All this behavior can bedetermined dynamically by control logic 240 that may include amicrocontroller or other computing device executing machine instructionsread from a computer-readable medium 244. Within this context, thebehavior of the analog-to-digital (ADC) converter 250 may be controlledin part by the configuration of the column switching register 220 and/orrow switching register 230, as well as the control logic 240. Forexample, based on the configuration of the column switching register 220and row switching register 230, the ADC 250 may be configured forspecific modes of operation that are compatible with the type of sensingassociated with the column switching register 220/row switching register230 setup.

FIG. 3 illustrates 300 an exemplary variable impedance array sensor 310in which the interlinked impedance columns 320 form a reduced electricalinterface to the physical variable impedance array sensor columns 3123that comprise the variable impedance array sensor array 310. Similarly,the interlinked impedance rows 330 form a reduced electrical interfaceto the physical variable impedance array sensor rows 313 that comprisethe variable impedance array sensor array 310. Note in this example thatthe number of physical variable impedance array columns 312 need not bethe same as the number of physical variable impedance array rows 313.Furthermore, the number of column interpolation impedance components (X)serially connecting each column of the variable impedance array 310 neednot be equal to the number of row interpolation impedance components (Y)serially connecting each row of the variable impedance array 310. Inother words, the number of interpolated columns 322, 324 need not beequal to the number of interpolated rows 332, 334.

The control logic 340 provides information to control the state of thecolumn switches 321, 323, 325 and row switches 331, 333, 335. The columnswitches 321, 323, 325 define whether the individual variable impedancearray columns are grounded or driven to a voltage potential from avoltage source 327 that may in some embodiments be adjustable by thecontrol logic 340 to allow on-the-fly adjustment 341 which can be usedto compensate for potential non-linearities in the driving electronics.Similarly, the row switches 331, 333, 335 define whether an individualvariable impedance array row is grounded or electrically coupled to thesignal conditioner 360 and associated ADC 350.

In the configuration depicted in FIG. 3, the variable impedance arraysensors 310 comprise uniformly two interpolating impedances between eachcolumn (X) and three interpolating impedances between each row (Y). Thisillustrates the fact that the number of interpolating columns need notequal the number of interpolating rows in a given variable impedancearray. Furthermore, it should be noted that the number of interpolatingcolumns need not be uniform across the variable impedance array, nordoes the number of interpolating rows need be uniform across thevariable impedance array. Each of these parameters may vary in numberacross the variable impedance array.

Note also that the variable impedance array sensors 310 need not haveuniformity within the row or column interpolating impedances and thatthese impedances in some circumstances may be defined dynamically innumber and/or value using MOSFETs or other transconductors. In thisexemplary variable impedance array sensor segment, it can be seen thatone column 323 of the array is actively driven while the remaining twocolumns 321, 325 are held at ground potential. The rows are configuredsuch that one row 333 is being sensed by the signal conditioner 360/ADCcombination 350 while the remaining rows 331, 335 are held at groundpotential.

FIG. 4 illustrates an exemplary embodiment 400 of an automotive touchsensor detector incorporating an interpolated variable impedance touchsensor array. In this embodiment, interpolated variable impedance touchsensor arrays 411, 412, 413, 414 are incorporated into a steering wheel450. The interpolated variable impedance touch sensor arrays 411, 412,413, 414 are communicatively coupled to a processor programmed toreceive pressure information from the sensor array. As described aboveand in the incorporated references, the sensor array is designed toprovide a continuous pressure gradient over a specified interval. Toaccomplish this, the sensor array preferably has a distance betweenadjacent sensor elements smaller than finger width. The interpolatedvariable impedance touch sensor arrays 411, 412, 413, 414 areillustrated as sections near the thumb and fingers of a driver duringnormal driving operations. The interpolated variable impedance touchsensor arrays 411, 412, 413, 414 may be located in or on the front sideof the steering wheel 450 and/or the back side of the steering wheel450.

FIG. 5 illustrates an alternate embodiment 500 of an automotive touchsensor detector incorporating an interpolated variable impedance touchsensor array. In this embodiment, the variable impedance touch sensorarray or arrays 525 may encompass part or all of the surface 525 of thesteering wheel 550. The interpolated variable impedance touch sensorarrays 525 are communicatively coupled to a processor programmed toreceive pressure information from the sensor array. As described aboveand in the incorporated references, the sensor array is designed toprovide a continuous pressure gradient over a specified interval. Toaccomplish this, the sensor array preferably has a distance betweenadjacent sensor elements smaller than finger width. The interpolatedvariable impedance touch sensor arrays 525 may be located in or on thefront side of the steering wheel 550 and/or the back side of thesteering wheel 550.

In one example, the steering wheel 450, 550 includes variable impedancetouch sensor arrays that comprise swipeable and/or pressable controls onthe front and/or back surface of the steering wheel 450, 550. Suchcontrols enable the driver to control automotive functions whilemaintaining hands on the wheel. In some embodiments, the variableimpedance touch sensor arrays comprise controls to operate anautomobile's headlights, wipers, and blinker. Additionally, using thecontinuous pressure response of the variable impedance touch sensorarrays, the controls can control the magnitude of the response relativeto the amount of pressure applied to the variable impedance touch sensorarrays. For example, the sensors could control the speed of the swipingmotion of windshield wipers relative to the amount of pressure appliedto the array or section of an array assigned to controlling the wiperblades. Or the force controls using variable impedance touch sensorarrays can be used for audio controls including selecting an audiosource, changing channels, or advancing or sending a reverse or rewindcommand based on the location of the touch on the steering wheel 450,550. And the volume can be controlled relative to the amount of pressureof the touch on the variable impedance touch sensor arrays. In additionto control of automotive function and audio are specifically, thesensors may be used to control other automotive functions. For example,the sensor and system described may be used to launch an application orperform an action on a connected device (e.g. driver's phone), select adestination on a map, switch the function that an input surfacecontrols, etc.

In another embodiment, variable impedance touch sensor arrays areembedded in the steering wheel 450, 550 such that the variable impedancetouch sensor arrays can detect a driver's grip or squeeze of part of thesteering wheel 450, 550. The coupled processor may be programmed toapply a control signal to the automobile based on the grip or squeeze,sequence of grips or squeezes, and/or pattern of grips and or squeezes.For example, a double squeeze (or similar or more complex pattern) couldbe used to power on an automate device or send a control signal tosystems in the car (e.g., audio systems, cruise control, lighting,etc.). One advantage of requiring patterns or sequences of grips orsqueezes is to differentiate between spurious pressure and desiredactions and thereby reject spurious inputs. FIG. 6 illustrates anexemplary embodiment of such a system that uses a grip or squeezepattern to reject spurious inputs. As shown in the graph 600 of FIG. 6,three sequential grips 601, 602, 603 are received at the steering wheel.This specific pattern (within a given threshold) can be recognized andused to send control signals to automotive systems.

In one example, a squeeze or grip is used to select an item in one ofthe automotive systems (e.g., audio, lighting, navigation, etc.). In oneexample, the squeeze or grip may be used for car navigation, so thedriver does not have to interact with a navigation screen.Alternatively, such systems may be used to transfer control ofautonomous vehicles back to a driver. For example, in an autonomousvehicle equipped with a steering wheel, the driver could squeeze or gripthe wheel with a threshold force and/or pattern to take control of thevehicle. Similarly, the grip or squeeze strength and/or pattern could beused to control acceleration and/or braking of a vehicle.

In additional embodiments, the variable impedance touch sensor arraysincorporated in the steering wheel 450, 550 may be used to detect whenthe driver is not adequately gripping the steering wheel 450, 550. Forexample, if the driver becomes drowsy or is distracted, the system mayuse the continuous pressure information from the variable impedancetouch sensor arrays to determine that the driver needs an alert or thatother safety measures need to be implemented (e.g., slowing the vehicledown or initiating an alarm). Additionally, because the variableimpedance touch sensor arrays can be used to determine continuouspressure patterns, the includes variable impedance touch sensor arraydata to generate a force profile that can be used to determine if thedriver is driving with limited control of the steering wheel 450, 550(e.g., driving with one hand or with a knee on the wheel). The system'sability to distinguish light exploratory touch from more forcefulintentional touch allows for real-time non-visual feedback (e.g.auditory). For example, it allows controls to say their function whentouched and execute when pressed. It also allows the driver to find thelocation of the controls by touch without accidental activation.Similarly, the system has the ability to provide continuous feedbackfrom very light touch to very firm.

The variable impedance touch sensor arrays of the present invention maybe incorporated in various surfaces (e.g., steering wheel, dash board,center console, gear shifter, arm rest, door interior and handle, sunvisor, control levers) in an automobile to create control surfaces. Suchcontrol surfaces (particularly those convenient for the driver to reachlike the arm rest and steering wheel) advantageously reduce a driver'sreliance on visual cues like those from a touch screen or standard knobsand similar conventional interfaces thereby improving the driver'sability to maintain eye contact with the road. The variable impedancetouch sensor arrays may be incorporated under the surface covering(e.g., leather, vinyl, plastic, fabric) of the surface. The arrays mayhave outlines stitched into the covering material or printed indicatorsor LED to make area glow to indicate the touch sensitive areas to thedriver.

For example, FIG. 7 illustrates an interior 700 of an automobileincorporating variable impedance touch sensor arrays of the presentinvention may be incorporated in various surfaces of the interior. Asillustrated in FIG. 7, the variable impedance touch sensor arrays of thepresent invention may be incorporated into the dash 710, 711. Thevariable impedance touch sensor arrays of the present invention may beincorporated in the dash near the passenger 710 and/or near the driver711. The variable impedance touch sensor arrays of the present inventionmay be incorporated in the surface of the brake pedal 712 and/or the gaspedal 713. In addition, variable impedance touch sensor arrays of thepresent invention may be incorporated into the console 714 of theautomobile.

The interpolated variable impedance touch sensor arrays 710, 711, 712,713, 714 are communicatively coupled to a processor programmed toreceive pressure information from the sensor array. As described aboveand in the incorporated references, the sensor array is designed toprovide a continuous pressure gradient over a specified interval. Toaccomplish this, the sensor array preferably has a distance betweenadjacent sensor elements smaller than finger width. In one example, atouch (or pattern of touches) to the variable impedance touch sensorarrays 710, 711, 712, 713, 714 is used to select an item in one of theautomotive systems (e.g., audio, lighting, navigation, etc.). In oneexample, touch may be used for car navigation, so the driver does nothave to interact with a navigation screen. Alternatively, such systemsmay be used to transfer control of autonomous vehicles back to a driver.

In addition, the system may use the data from the interpolated variableimpedance touch sensor arrays in the gas pedal 712 and/or brake pedal713 for control of the acceleration and/or deceleration of theautomobile. For example, the force applied to the gas pedal sensor 712may be used to control acceleration, and the force applied to the brakepedal sensor 713 may be used to control deceleration. Additionally, thesystem may use patterns of touches or applications of force to the pedalsensors 712, 713 to control the automobile.

With the variable impedance touch sensor arrays disclosed herein,essential or common controls can be moved into the steering wheel (orother surfaces as described above) itself. The disclosed sensors allowincorporation of touch arrays on the outside of the steering wheel andother surfaces even when covered with leather, vinyl, or other texturedmaterial (e.g., to ensure that the driver can have a good grip on thewheel). With the disclosed variable impedance touch sensor arraytechnology, the sensors may be incorporated into the outer area of thesteering wheel (and other surfaces) itself. This way the driver does notneed his or her hands away from the safe positions on the steering wheelto make commands.

In some embodiments, the control surfaces also include haptic feedbackdevices for providing feedback to the driver based on the driver's touchinput. In some embodiments, the sensor arrays are used to determinepatterns or gestures on the control surfaces that are used to controlautomotive systems including mirrors, cameras, audio, environmentalcontrols, lighting, seat placement, seat adjustments, headlights,external lights, and turn signals.

In other embodiments, as shown in FIG. 8 for example, the variableimpedance touch sensor arrays 810, 810 of the present invention may beincorporated into seats and/or seatbelts 800. With the disclosedvariable impedance touch sensor array technology, the sensors 810, 820may be incorporated into material of the seatbelt (e.g., fabric, plasticof the buckle) and/or seat (e.g., fabric, vinyl, leather) of the seat.Seat belt sensors may be used to check for proper fit. This would beespecially advantageous in child seats and/or for seats occupied bychildren, both situations in which proper seatbelt placement isdifficult. The variable impedance touch sensor arrays incorporated inthe seatbelt and/or seat can be used to determine instantaneous forcesignatures and patterns over time to determine that the fit of the beltand/or seat is proper. Additionally, the variable impedance touch sensorarrays could be used to redistribute and/or realign seats to accommodateoccupants based on their instantaneous force signatures and patternsover time. In other embodiments, the variable impedance touch sensorarrays can be used to provide input to automotive systems (such assteering or the other systems described above) for example by placingpressure or shifting weight to one area of the seat.

As illustrated in FIG. 9, the variable impedance touch sensor arrays910, 911 may be incorporated in other surfaces of the automobileincluding the interior roof 900 of the automobile. The variableimpedance touch sensor arrays 910, 911 may be incorporated in a small orlarge portion of a surface of the roof 900. The variable impedance touchsensor arrays 910, 911 may provide touch and/or pressure data that thesystem may use to control elements of the automobile such as windows orsun visors. Because of the continuous pressure response data providedfrom the variable impedance touch sensor arrays 910, 911, the data maycontrol the state of the controlled device (e.g., on/off or open/closed)as well as the rate of the change between states.

FIG. 10 illustrates a further embodiment in which the variable impedancetouch sensor arrays of the present invention are incorporated insurfaces of an automobile as shown in FIGS. 7 and 9. As shown in FIG.10, the touch surface 1014 defined by the variable impedance touchsensor arrays may cover a large surface 1014 such as that shown largerthan the hand of a user. The variable impedance touch sensor arrays ofthe present invention may be incorporated into a large-scale surface invarious interior surfaces including the dash near the passenger and/ornear the driver as well as in surfaces such as the surface of the brakepedal and/or the gas pedal. Additionally, the large-scale surface withvariable impedance touch sensor arrays of the present invention isadvantageously incorporated into the console of the automobile.

The interpolated variable impedance touch sensor arrays in the surface1014 are communicatively coupled to a processor programmed to receivepressure information from the sensor array. As described above and inthe incorporated references, the sensor array is designed to provide acontinuous pressure gradient over a specified interval. To accomplishthis, the sensor array preferably has a distance between adjacent sensorelements smaller than finger width. In one example, a touch (or patternof touches) to the variable impedance touch sensor arrays in the surface1014 is used to select an item in one of the automotive systems (e.g.,audio, lighting, navigation, etc.). In one example, touch may be usedfor car navigation, so the driver does not have to interact with anavigation screen. Alternatively, such systems may be used to transfercontrol of autonomous vehicles back to a driver.

With the variable impedance touch sensor arrays disclosed herein,essential or common controls can be moved into the steering wheel (orother surfaces as described above) itself. The disclosed sensors allowincorporation of touch arrays on the outside of the steering wheel andother surfaces even when covered with leather, vinyl, or other texturedmaterial (e.g., to ensure that the driver can have a good grip on thewheel). With the disclosed variable impedance touch sensor arraytechnology, the sensors may be incorporated into the outer area of thesteering wheel (and other surfaces) itself. This way the driver does notneed his or her hands away from the safe positions on the steering wheelto make commands.

In some embodiments, the control surfaces also include haptic feedbackdevices for providing feedback to the driver based on the driver's touchinput. In some embodiments, the sensor arrays are used to determinepatterns or gestures on the control surfaces that are used to controlautomotive systems including mirrors, cameras, audio, environmentalcontrols, lighting, seat placement, seat adjustments, headlights,external lights, and turn signals.

In addition to the systems disclosed above, the present inventionrelates to automotive touch sensor detector methods incorporating aninterpolated variable impedance touch sensor array. The methodsdisclosed herein utilize a touch sensor array configured to detectproximity/contact/pressure via a variable impedance array electricallycoupling interlinked impedance columns coupled to an array column driverand interlinked impedance rows coupled to an array row sensor. The arraycolumn driver is configured to select the interlinked impedance columnsbased on a column switching register and electrically drive theinterlinked impedance columns using a column driving source. Thevariable impedance array conveys current from the driven interlinkedimpedance columns to the interlinked impedance columns sensed by thearray row sensor. The array row sensor selects the interlinked impedancerows within the touch sensor array and electrically senses theinterlinked impedance rows state based on a row switching register.Interpolation of array row sensor sensed current/voltage allows accuratedetection of touch sensor array proximity/contact/pressure and/orspatial location.

In one embodiment 1105 as illustrated in FIG. 11, the method 1100includes providing an interpolated variable impedance array disposed onor about the steering wheel comprising a grid of sensing elements 1110.The grid of sensing elements powers on simultaneously 1120 and thensimultaneously generates multiple currents along multiple current pathsin response to sensing a touch 1130, wherein the amount of currentgenerated by a sensing element of the grid is directly proportional tothe force applied by the touch. Thereafter an ADC and a processor(communicatively coupled to the interpolated variable impedance array)receive the multiple currents along multiple current paths 1140 anddetermine a location, a duration, an area, and a force of the touch fromthe multiple currents along multiple current paths 1150. Theinterpolated variable impedance array may be disposed on the front sideof the steering wheel or on the back side of the steering wheel forexample. The interpolated variable impedance array may compriseswipeable and/or pressable controls.

In a further embodiment, the method 1100 includes the variable impedancearray and the processor controlling one or more of the automobile'sheadlights, wipers, or blinkers 1160. And as shown in FIG. 12, themethod 1105 shown in FIG. 11 may further comprise the interpolatedvariable impedance array and the processor determining an amount ofpressure applied to the variable impedance touch sensor array 1210 aswell as the interpolated variable impedance array and the processorcontrolling an audio source relative to the amount of pressure appliedto the variable impedance touch sensor array 1220. Also, as shown inFIG. 12, the method 1105 shown in FIG. 11 may further comprise theinterpolated variable impedance array and the processor detecting adriver's grip force of the steering wheel 1230, applying a controlsignal based on the driver's grip force of the steering wheel 1240, andapplying a control signal based on a pattern of the driver's grip forceof the steering wheel 1250.

The method 1105 shown in FIG. 11 may further include the interpolatedvariable impedance array and the processor are determining that thedriver's grip force of the steering wheel is inadvertent or spurious1260. Moreover, the method 1105 shown in FIG. 11 may include theinterpolated variable impedance array and the processor determining whenthe driver is not gripping the steering wheel above a threshold level1270 and sending a signal to cause an autonomous or semiautonomousvehicle to return control to a driver 1280 or determining when a driverhas only one hand on the steering wheel 1290.

Additional methods include providing an interpolated variable impedancearray disposed on or about the seat belt comprising a grid of sensingelements. The grid of sensing elements powering on simultaneously andsimultaneously generating multiple currents along multiple current pathsin response to sensing a touch wherein the amount of current generatedby a sensing element of the grid is directly proportional to the forceapplied by the touch. Thereafter, an ADC and a processor(communicatively coupled to the interpolated variable impedance array)receive the multiple currents along multiple current paths and determinea location, a duration, an area, and a force of the touch from themultiple currents along multiple current paths.

The ADC and a processor may further determine a fit of the seat belt ona passenger, determine instantaneous force signatures and patterns overtime to determine that the fit of the seat belt, and/or send a controlsignal to realign a seat based on the instantaneous force signatures andpatterns over time.

A further method includes providing an interpolated variable impedancearray disposed on or about the acceleration pedal comprising a grid ofsensing elements. The grid of sensing elements power on simultaneouslyand simultaneously generate multiple currents along multiple currentpaths in response to sensing a touch wherein the amount of currentgenerated by a sensing element of the grid is directly proportional tothe force applied by the touch. Then an ADC and a processor(communicatively coupled to the interpolated variable impedance array)receive the multiple currents along multiple current paths and determinea location, a duration, an area, and a force of the touch from themultiple currents along multiple current paths.

In the present specification, the term “or” is intended to mean aninclusive “or” rather than an exclusive “or.” That is, unless specifiedotherwise, or clear from context, “X employs A or B” is intended to meanany of the natural inclusive permutations. That is, if X employs A; Xemploys B; or X employs both A and B, then “X employs A or B” issatisfied under any of the foregoing instances. Moreover, articles “a”and “an” as used in this specification and annexed drawings shouldgenerally be construed to mean “one or more” unless specified otherwiseor clear from context to be directed to a singular form.

In addition, the terms “example” and “such as” are utilized herein tomean serving as an instance or illustration. Any embodiment or designdescribed herein as an “example” or referred to in connection with a“such as” clause is not necessarily to be construed as preferred oradvantageous over other embodiments or designs. Rather, use of the terms“example” or “such as” is intended to present concepts in a concretefashion. The terms “first,” “second,” “third,” and so forth, as used inthe claims and description, unless otherwise clear by context, is forclarity only and does not necessarily indicate or imply any order intime.

What has been described above includes examples of one or moreembodiments of the disclosure. It is, of course, not possible todescribe every conceivable combination of components or methodologiesfor purposes of describing these examples, and it can be recognized thatmany further combinations and permutations of the present embodimentsare possible. Accordingly, the embodiments disclosed and/or claimedherein are intended to embrace all such alterations, modifications andvariations that fall within the spirit and scope of the detaileddescription and the appended claims. Furthermore, to the extent that theterm “includes” is used in either the detailed description or theclaims, such term is intended to be inclusive in a manner similar to theterm “comprising” as “comprising” is interpreted when employed as atransitional word in a claim.

What is claimed is:
 1. A vehicle interface system comprising: aninterpolated variable impedance array disposed on or about a steeringwheel, the interpolated variable impedance array comprising a grid ofsensing elements that are configured to power on simultaneously and tosimultaneously generate multiple currents along multiple current pathsin response to sensing a touch, wherein an amount of current generatedby a sensing element of the grid of sensing elements is directlyproportional to a force applied by the touch, and wherein theinterpolated variable impedance array facilitates a continuous pressuregradient based on a defined distance between adjacent sensing elementsof the grid of sensing elements; and an analog-to-digital converter anda processor communicatively coupled to the interpolated variableimpedance array and configured to receive the multiple currents alongmultiple current paths and determine a location, a duration, an area,and the force of the touch from the multiple currents along multiplecurrent paths.
 2. The vehicle interface system of claim 1, wherein theinterpolated variable impedance array and the processor are configuredto facilitate control of a vehicle operation based on a patternassociated with the touch.
 3. The vehicle interface system of claim 2,wherein the pattern is a first pattern that indicates a first actionassociated with the vehicle operation, and wherein the interpolatedvariable impedance array and the processor are further configured todifferentiate the first pattern from a second pattern that indicates asecond action associated with the vehicle operation.
 4. The vehicleinterface system of claim 2, wherein the pattern is a first pattern thatindicates a first action associated with the vehicle operation, andwherein the interpolated variable impedance array and the processor arefurther configured to: differentiate the first pattern from a secondpattern, wherein the second pattern is a spurious input; and reject thesecond pattern as being an inadvertent input.
 5. The vehicle interfacesystem of claim 2, wherein the interpolated variable impedance array andthe processor are configured to transfer control of the vehicleoperation to a driver based on the pattern associated with the touch. 6.The vehicle interface system of claim 1, wherein the interpolatedvariable impedance array and the processor are configured to facilitatean auditory response based on the touch, wherein the auditory responsecomprises an indication of a function defined for the touch.
 7. Thevehicle interface system of claim 1, wherein the interpolated variableimpedance array and the processor are configured to control wipers. 8.The vehicle interface system of claim 1, wherein the interpolatedvariable impedance array and the processor are configured to controlblinkers.
 9. The vehicle interface system of claim 1, wherein theinterpolated variable impedance array and the processor are configuredto control vehicle navigation.
 10. The vehicle interface system of claim9, wherein the interpolated variable impedance array and the processorare configured to select a destination of a map based on the touch. 11.The vehicle interface system of claim 1, wherein the steering wheelcomprises a surface covering, and wherein the interpolated variableimpedance array is disposed on or about the steering wheel under thesurface covering.
 12. The vehicle interface system of claim 11, furthercomprising a light emitting diode located on or about the steeringwheel, wherein the light emitting diode indicates a touch locationassociated with the interpolated variable impedance array.
 13. A vehicleinterface system, comprising: an interpolated variable impedance arraydisposed on or about a vehicle control pedal, the interpolated variableimpedance array comprising a grid of sensing elements that areconfigured to power on simultaneously and to simultaneously generatemultiple currents along multiple current paths in response to sensing atouch, wherein an amount of current generated by a sensing element ofthe grid of sensing elements is directly proportional to a force appliedby the touch, and wherein the interpolated variable impedance arrayfacilitates a continuous pressure gradient based on a defined distancebetween adjacent sensing elements of the grid of sensing elements; andan analog-to-digital converter and a processor communicatively coupledto the interpolated variable impedance array and configured to receivethe multiple currents along multiple current paths and determine alocation, a duration, an area, and the force of the touch from themultiple currents along multiple current paths.
 14. The vehicleinterface system of claim 13, wherein the vehicle control pedal is anaccelerator pedal, and wherein the processor is configured to control amagnitude of acceleration based on an amount of pressure applied to theinterpolated variable impedance array.
 15. The vehicle interface systemof claim 13, wherein the vehicle control pedal is a brake pedal, andwherein the processor is configured to control a magnitude ofdeceleration based on an amount of pressure applied to the interpolatedvariable impedance array.
 16. The vehicle interface system of claim 13,wherein the interpolated variable impedance array and the processor areconfigured to facilitate control of a vehicle operation based on apattern associated with the touch.
 17. The vehicle interface system ofclaim 16, wherein the vehicle control pedal is an accelerator pedal, andwherein the processor is configured to facilitate an amount ofacceleration based on the pattern indicating the amount of accelerationto be applied.
 18. The vehicle interface system of claim 16, wherein thevehicle control pedal is a brake pedal, and wherein the processor isconfigured to facilitate an amount of deceleration based on the patternindicating an amount of braking action to be applied.
 19. A vehicleinterface system, comprising: an interpolated variable impedance arraydisposed on or about one or more of a gear shifter, a dash board, aninterior roof, a center console, an arm rest, a sun visor, and a controllever, the interpolated variable impedance array comprising a grid ofsensing elements that are configured to power on simultaneously and tosimultaneously generate multiple currents along multiple current pathsin response to sensing a touch, wherein an amount of current generatedby a sensing element of the grid of sensing elements is directlyproportional to a force applied by the touch, and wherein theinterpolated variable impedance array facilitates a continuous pressuregradient based on a defined distance between adjacent sensing elementsof the grid of sensing elements; and an analog-to-digital converter anda processor communicatively coupled to the interpolated variableimpedance array and configured to receive the multiple currents alongmultiple current paths and determine a location, a duration, an area,and the force of the touch from the multiple currents along multiplecurrent paths.
 20. The vehicle interface system of claim 19, wherein amagnitude of response associated with the touch is relative to an amountof pressure applied to the at least one of the gear shifter, the dashboard, the interior roof, the center console, the arm rest, the sunvisor, and the control lever.